Defining a “block trade” in the swaps market is one of the many jobs of the regulators in the next few months. As this story points out, average trade sizes for swaps change drastically based on product and market conditions making it pretty difficult to set a single number. Maybe more important is the reporting delay allowed for block trades giving dealers a little more flexibility in what they show the world and when:

The block trade reporting exemption could provide some welcome flexibility for dealers, according to Kevin McPartland, senior research analyst at TABB Group. It “creates an environment where trades can still be executed bilaterally as long as they are ultimately reported to a SEF and the SEF reports that trade to the regulators after the decided time delay,” he wrote in a soon-to-be-published research note.